Sulfur amino acids regulate translational capacity and metabolic homeostasis through modulation of tRNA thiolation.

Protein translation is an energetically demanding process that must be regulated in response to changes in nutrient availability. Herein, we report that intracellular methionine and cysteine availability directly controls the thiolation status of wobble-uridine (U34) nucleotides present on lysine, glutamine, or glutamate tRNAs to regulate cellular translational capacity and metabolic homeostasis. tRNA thiolation is important for growth under nutritionally challenging environments and required for efficient translation of genes enriched in lysine, glutamine, and glutamate codons, which are enriched in proteins important for translation and growth-specific processes. tRNA thiolation is downregulated during sulfur starvation in order to decrease sulfur consumption and growth, and its absence leads to a compensatory increase in enzymes involved in methionine, cysteine, and lysine biosynthesis. Thus, tRNA thiolation enables cells to modulate translational capacity according to the availability of sulfur amino acids, establishing a functional significance for this conserved tRNA nucleotide modification in cell growth control.

A gain-of-function mutation in DHT synthesis in castration-resistant prostate cancer.

Growth of prostate cancer cells is dependent upon androgen stimulation of the androgen receptor (AR). Dihydrotestosterone (DHT), the most potent androgen, is usually synthesized in the prostate from testosterone secreted by the testis. Following chemical or surgical castration, prostate cancers usually shrink owing to testosterone deprivation. However, tumors often recur, forming castration-resistant prostate cancer (CRPC). Here, we show that CRPC sometimes expresses a gain-of-stability mutation that leads to a gain-of-function in 3ß-hydroxysteroid dehydrogenase type 1 (3ßHSD1), which catalyzes the initial rate-limiting step in conversion of the adrenal-derived steroid dehydroepiandrosterone to DHT. The mutation (N367T) does not affect catalytic function, but it renders the enzyme resistant to ubiquitination and degradation, leading to profound accumulation. Whereas dehydroepiandrosterone conversion to DHT is usually very limited, expression of 367T accelerates this conversion and provides the DHT necessary to activate the AR. We suggest that 3ßHSD1 is a valid target for the treatment of CRPC.

Influence of Interlayer Cation Ordering on Na Transport in P2-Type Na0.67-xLiy Ni0.33-zMn0.67+zO2 for Sodium-Ion Batteries.

P2-type Na2/3Ni1/3Mn2/3O2 (PNNMO) has been extensively studied because of its desirable electrochemical properties as a positive electrode for sodium-ion batteries. PNNMO exhibits intralayer transition-metal ordering of Ni and Mn and intralayer Na+/vacancy ordering. The Na+/vacancy ordering is often considered a major impediment to fast Na+ transport and can be affected by transition-metal ordering. We show by neutron/X-ray diffraction and density functional theory (DFT) calculations that Li doping (Na2/3Li0.05Ni1/3Mn2/3O2, LFN5) promotes ABC-type interplanar Ni/Mn ordering without disrupting the Na+/vacancy ordering and creates low-energy Li-Mn-coordinated diffusion pathways. A structure model is developed to quantitatively identify both the intralayer cation mixing and interlayer cationic stacking fault densities. Quasielastic neutron scattering reveals that the Na+ diffusivity in LFN5 is enhanced by an order of magnitude over PNNMO, increasing its capacity at a high current. Na2/3Ni1/4Mn3/4O2 (NM13) lacks Na+/vacancy ordering but has diffusivity comparable to that of LFN5. However, NM13 has the smallest capacity at a high current. The high site energy of Mn-Mn-coordinated Na compared to that of Ni-Mn and higher density of Mn-Mn-coordinated Na+ sites in NM13 disrupts the connectivity of low-energy Ni-Mn-coordinated diffusion pathways. These results suggest that the interlayer ordering can be tuned through the control of composition, which has an equal or greater impact on Na+ diffusion than the Na+/vacancy ordering.

Tumour-associated macrophages and Schwann cells promote perineural invasion via paracrine loop in pancreatic ductal adenocarcinoma.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is frequently accompanied by perineural invasion (PNI), which is associated with excruciating neuropathic pain and malignant progression. However, the relationship between PNI and tumour stromal cells has not been clarified. METHODS: The dorsal root ganglia or sciatic nerves nerve model was used to observe the paracrine interaction and the activation effect among Schwann cells, tumour-associated macrophages (TAMs), and pancreatic cancer cells in vitro. Next generation sequencing, enzyme-linked immunosorbent assay and chromatin immunoprecipitation were used to explore the specific paracrine signalling between TAMs and Schwann cells. RESULTS: We demonstrated that more macrophages were expressed around nerves that have been infiltrated by pancreatic cancer cells compared with normal nerves in murine and human PNI specimens. In addition, high expression of CD68 or GFAP is associated with an increased incidence of PNI and indicates a poor 5-year survival rate in patients with PDAC. Mechanistically, tumour-associated macrophages (TAMs) activate Schwann cells via the bFGF/PI3K/Akt/c-myc/GFAP pathway. Schwann cells secrete IL-33 to recruit macrophages into the perineural milieu and facilitate the M2 pro-tumourigenic polarisation of macrophages. CONCLUSIONS: Our study demonstrates that the bFGF/IL-33 positive feedback loop between Schwann cells and TAMs is essential in the process of PNI of PDAC. The bFGF/PI3K/Akt/c-myc/GFAP pathway would open potential avenues for targeted therapy of PDAC.

Text-to-Microstructure Generation Using Generative Deep Learning.

Designing novel materials is greatly dependent on understanding the design principles, physical mechanisms, and modeling methods of material microstructures, requiring experienced designers with expertise and several rounds of trial and error. Although recent advances in deep generative networks have enabled the inverse design of material microstructures, most studies involve property-conditional generation and focus on a specific type of structure, resulting in limited generation diversity and poor human-computer interaction. In this study, a pioneering text-to-microstructure deep generative network (Txt2Microstruct-Net) is proposed that enables the generation of 3D material microstructures directly from text prompts without additional optimization procedures. The Txt2Microstruct-Net model is trained on a large microstructure-caption paired dataset that is extensible using the algorithms provided. Moreover, the model is sufficiently flexible to generate different geometric representations, such as voxels and point clouds. The model's performance is also demonstrated in the inverse design of material microstructures and metamaterials. It has promising potential for interactive microstructure design when associated with large language models and could be a user-friendly tool for material design and discovery.

Tailoring the d-band center on Ru1Cu single-atom alloy nanotubes for boosting electrochemical non-enzymatic glucose sensing.

The development of cost-effective and highly efficient electrocatalysts is critical to help electrochemical non-enzymatic sensors achieve high performance. Here, a new class of catalyst, Ru single atoms confined on Cu nanotubes as a single-atom alloy (Ru1Cu NTs), with a unique electronic structure and property, was developed to construct a novel electrochemical non-enzymatic glucose sensor for the first time. The Ru1Cu NTs with a diameter of about 24.0 nm showed a much lower oxidation potential (0.38 V) and 9.0-fold higher response (66.5 µA) current than Cu nanowires (Cu NWs, oxidation potential 0.47 V and current 7.4 µA) for glucose electrocatalysis. Moreover, as an electrochemical non-enzymatic glucose sensor, Ru1Cu NTs not only exhibited twofold higher sensitivity (54.9 µA mM-1 cm-2) and wider linear range (0.5-8 mM) than Cu NWs, but also showed a low detection limit (5.0 µM), excellent selectivity, and great stability. According to theoretical calculation results, the outstanding catalytic and sensing performance of Ru1Cu NTs could be ascribed to the upshift of the d-band center that helped promote glucose adsorption. This work presents a new avenue for developing highly active catalysts for electrochemical non-enzymatic sensors.

Genetically predicted high sex hormone binding globulin was associated with decreased risk of polycystic ovary syndrome.

BACKGROUND: Previous observational studies have indicated an inverse correlation between circulating sex hormone binding globulin (SHBG) levels and the incidence of polycystic ovary syndrome (PCOS). Nevertheless, conventional observational studies may be susceptible to bias. Consequently, we conducted a two-sample Mendelian randomization (MR) investigation to delve deeper into the connection between SHBG levels and the risk of PCOS. METHODS: We employed single-nucleotide polymorphisms (SNPs) linked to serum SHBG levels as instrumental variables (IVs). Genetic associations with PCOS were derived from a meta-analysis of GWAS data. Our primary analytical approach relied on the inverse-variance weighted (IVW) method, complemented by alternative MR techniques, including simple-median, weighted-median, MR-Egger regression, and MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) testing. Additionally, sensitivity analyses were conducted to assess the robustness of the association. RESULTS: We utilized 289 SNPs associated with serum SHBG levels, achieving genome-wide significance, as instrumental variables (IVs). Our MR analyses revealed that genetically predicted elevated circulating SHBG concentrations were linked to a reduced risk of PCOS (odds ratio (OR) = 0.56, 95% confidence interval (CI): 0.39-0.78, P = 8.30 × 10-4) using the IVW method. MR-Egger regression did not detect any directional pleiotropic effects (P intercept = 0.626). Sensitivity analyses, employing alternative MR methods and IV sets, consistently reaffirmed our results, underscoring the robustness of our findings. CONCLUSIONS: Through a genetic epidemiological approach, we have substantiated prior observational literature, indicating a potential causal inverse relationship between serum SHBG concentrations and PCOS risk. Nevertheless, further research is needed to elucidate the underlying mechanism of SHBG in the development of PCOS.

TRIM44 Promotes Rabies Virus Replication by Autophagy-Dependent Mechanism.

Tripartite motif (TRIM) proteins are a multifunctional E3 ubiquitin ligase family that participates in various cellular processes. Recent studies have shown that TRIM proteins play important roles in regulating host-virus interactions through specific pathways, but their involvement in response to rabies virus (RABV) infection remains poorly understood. Here, we identified that several TRIM proteins are upregulated in mouse neuroblastoma cells (NA) after infection with the rabies virus using RNA-seq sequencing. Among them, TRIM44 was found to regulate RABV replication. This is supported by the observations that downregulation of TRIM44 inhibits RABV replication, while overexpression of TRIM44 promotes RABV replication. Mechanistically, TRIM44-induced RABV replication is brought about by activating autophagy, as inhibition of autophagy with 3-MA attenuates TRIM44-induced RABV replication. Additionally, we found that inhibition of autophagy with rapamycin reverses the TRIM44-knockdown-induced decrease in LC3B expression and autophagosome formation as well as RABV replication. The results suggest that TRIM44 promotes RABV replication by an autophagy-dependent mechanism. Our work identifies TRIM44 as a key host factor for RABV replication, and targeting TRIM44 expression may represent an effective therapeutic strategy.

[Analysis of a case of Kabuki syndrome due to a novel variant of KMT2D gene].

OBJECTIVE: To report on a case of Kabuki syndrome (KS) due to a novel variant of KMT2D gene. METHODS: A child diagnosed with KS at the Fujian Children's Hospital on July 25, 2022 was selected as the study subject. Whole exome sequencing was carried out for the child and her parents. Candidate variant was validated by Sanger sequencing and bioinformatic analysis. RESULTS: The child, a 4-month-old female, had presented with distinctive facial features, growth retardation, cardiac malformations, horseshoe kidney, hypothyroidism, and recurrent aspiration pneumonia. Whole exome sequencing revealed that she has harbored a heterozygous c.6285dup (p.Lys2096Ter) variant of the KMT2D gene. Sanger sequencing confirmed that neither of her parents had carried the same variant. The variant was previously unreported and may result in a truncated protein and loss of an enzymatic activity region. The corresponding site of the variant is highly conserved. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as pathogenic (PVS1+PS2+PM2_Supporting). CONCLUSION: The c.6285dup variant of the KMT2D gene probably underlay the KS in this child.

Bioinspired Total Synthesis of Cephalotaxus Diterpenoids and Their Structural Analogues.

Herein, we present a unified chemical synthesis of three subgroups of cephalotaxus diterpenoids. Key to the success lies in adopting a synthetic strategy that is inspired by biosynthesis but is opposite in nature. By employing selective one-carbon introduction and ring expansion operations, we have successfully converted cephalotane-type C18 dinorditerpenoids (using cephanolide B as a starting material) into troponoid-type C19 norditerpenoids and intact cephalotane-type C20 diterpenoids. This synthetic approach has enabled us to synthesize cephinoid H, 13-oxo-cephinoid H, 7-oxo-cephinoid H, fortalpinoid C, 7-epi-fortalpinoid C, cephanolide E, and 13-epi-cephanolide E. Furthermore, through the development of an intermolecular asymmetric Michael reaction between ß-oxo esters and ß-substituted enones, we have achieved the enantioselective synthesis of advanced intermediates within our synthetic sequence, thus formally realizing the asymmetric total synthesis of the cephalotaxus diterpenoids family.

Stepwise Crystallization of Millimeter Scale Thorium Cluster Single Crystals as a Bifunctional Platform for X-ray Detection and Shielding.

Monitoring and shielding of X-ray radiation are of paramount importance across diverse fields. However, they are frequently realized in separate protocols and a single material integrating both functions remained elusive. Herein, a hexanuclear cluster [Th6 (µ3 -OH)4 (µ3 -O)4 (H2 O)6 ](pba)6 (HCOO)6 (Th-pba-0D) incorporating high-Z thorium cations and 3-(pyridin-4-yl)benzoate ligands that can function as a brand-new dual-module platform for visible detection and efficient shielding of ionizing radiation is demonstrated. Th-pba-0D exhibits rather unique reversible radiochromism upon alternating X-ray and UV irradiation. Moreover, the millimeter scale crystal size of Th-pba-0D renders the penetration depth of X-ray visible to naked eye and leads to the unearthing of its high X-ray attenuation efficiency. Indeed, the shielding efficacy of Th-pba-0D is comparable to that of lead glass containing 40% PbO, and a Th-pba-0D pellet with a thickness of merely 1.2 mm can shield 99.73% X-ray (16 keV). These studies portend the possible utilization of thorium-bearing materials as a bifunctional platform for radiation detection and shielding.

Boosting Electrochemical Catalysis and Nonenzymatic Sensing Toward Glucose by Single-Atom Pt Supported on Cu@CuO Core-Shell Nanowires.

It is critical to develop high-performance electrocatalyst for electrochemical nonenzymatic glucose sensing. In this work, a single-atom Pt supported on Cu@CuO core-shell nanowires (Pt1 /Cu@CuO NWs) for electrochemical nonenzymatic glucose sensor is designed. Pt1 /Cu@CuO NWs exhibit excellent electrocatalytic oxidation toward glucose with 70 mV lower onset potential (0.131 V) and 2.4 times higher response current than Cu NWs. Sensors fabricated using Pt1 /Cu@CuO NWs also show high sensitivity (852.163 µA mM-1 cm-2 ), low detection limit (3.6 µM), wide linear range (0.01-5.18 µM), excellent selectivity, and great long-term stability. The outstanding sensing performance of Pt1 /Cu@CuO NWs, investigated by experiments and density functional theory (DFT) calculations, is attributed to the synergistic effect between Pt single atoms and Cu@CuO core-shell nanowires that generates strong binding energy of glucose on the nanowires. The work provides a new pathway for exploring highly active SACs for electrochemical nonenzymatic glucose sensor.

Autophagy Suppresses Ferroptosis by Degrading TFR1 to Alleviate Cognitive Dysfunction in Mice with SAE.

Sepsis-associated encephalopathy (SAE) is a serious complication of sepsis that is characterized by long-term cognitive impairment, which imposes a heavy burden on families and society. However, its pathological mechanism has not been elucidated. Ferroptosis is a novel form of programmed cell death that is involved in multiple neurodegenerative diseases. In the current study, we found that ferroptosis also participated in the pathological process of cognitive dysfunction in SAE, while Liproxstatin-1 (Lip-1) effectively inhibited ferroptosis and alleviated cognitive impairment. Additionally, since an increasing number of studies have suggested the crosstalk between autophagy and ferroptosis, we further proved the essential role of autophagy in this process and demonstrated the key molecular mechanism of the autophagy-ferroptosis interaction. Currently, we showed that autophagy in the hippocampus was downregulated within 3 days of lipopolysaccharide injection into the lateral ventricle. Moreover, enhancing autophagy ameliorated cognitive dysfunction. Importantly, we found that autophagy suppressed ferroptosis by downregulating transferrin receptor 1 (TFR1) in the hippocampus, thereby alleviating cognitive impairment in mice with SAE. In conclusion, our findings indicated that hippocampal neuronal ferroptosis is associated with cognitive impairment. In addition, enhancing autophagy can inhibit ferroptosis via degradation of TFR1 to ameliorate cognitive impairment in SAE, which shed new light on the prevention and therapy for SAE.

High Expression of FOXO3 in Gastric Cancer Tissues is Associated with Poor Prognosis and Immune Cell Infiltration.

BACKGROUND: The purpose of this study was to explore the role of FOXO3 in gastric cancer (GC). METHODS: Data on gastric cancer and normal tissues were collected from the TCGA and GTEx databases. Survival analysis was performed with the Kaplan-Meier method, and the ENCORI online analysis tool was used to predict potential interaction miRNA. The MCPCOUNTER and Tumor Immune Dysfunction and Exclusion (TIDE) algorithm were used to predict the relationship between immune infiltration and FOXO3. Finally, gene set enrichment analysis (GSEA) was used to explore the potential pathways of FOXO3 during the development of GC. RESULTS: We found that mRNA expression level of FOXO3 was remarkably higher in tumor tissue than in normal tissue, and poor prognoses of GC patients were correlated with higher expression of FOXO3. We also found that hsa-miR-18a-5p and hsa-miR-18b-5p can interact with FOXO3 and that high expression of hsa-miR-18a-5p and hsa-miR-18b-5p predicted better prognoses in GC patients. TP53 mutation was significantly associated with high FOXO3 expression, while ARID1A mutation was associated with low FOXO3 expression. Multiple immune cells were found to be related to the expression of FOXO3, and lower expression of FOXO3 may be better suited to immune checkpoint blockade treatment. CONCLUSIONS: We find that FOXO3 is a potential oncogene and that the transcript level of FOXO3 is related to the mutation of TP53 and ARID1A. In addition, FOXO3 may influence immune infiltration and different signal pathways through sponge adsorption of miRNA to impact the prognoses of stomach adenocarcinoma patients.

The Role of Ferroptosis in Nervous System Disorders.

Ferroptosis is distinct from other apoptotic forms of programmed cell death and is characterized by the accumulation of iron and lipid peroxidation. Iron plays a crucial role in the oxidation of lipids via the Fenton reaction with oxygen. Hence, iron accumulation causes phospholipid peroxidation which induces ferroptosis. Moreover, detoxification by glutathione is disrupted during ferroptosis. A growing number of studies have implicated ferroptosis in nervous system disorders such as depression, neurodegenerative disease, stroke, traumatic brain injury, and sepsis-associated encephalopathy. This review summarizes the pathogenesis of ferroptosis and its relationship with various nervous system disorders.

TRIM21 Promotes Rabies Virus Production by Degrading IRF7 through Ubiquitination.

Rabies, a highly fatal zoonotic disease, is a significant global public health threat. Currently, the pathogenic mechanism of rabies has not been fully elucidated, and no effective treatment for rabies is available. Increasing evidence shows that the tripartite-motif protein (TRIM) family of proteins participates in the host's regulation of viral replication. Studies have demonstrated the upregulated expression of tripartite-motif protein 21 (TRIM21) in the brain tissue of mice infected with the rabies virus. Related studies have shown that TRIM21 knockdown inhibits RABV replication, while overexpression of TRIM21 exerted the opposite effect. Knockdown of interferon-alpha and interferon-beta modulates the inhibition of RABV replication caused by TRIM21 knockdown and promotes the replication of the virus. Furthermore, our previous study revealed that TRIM21 regulates the secretion of type I interferon during RABV infection by targeting interferon regulatory factor 7 (IRF7). IRF7 knockdown reduced the inhibition of RABV replication caused by the knockdown of TRIM21 and promoted viral replication. TRIM21 regulates RABV replication via the IRF7-IFN axis. Our study identified TRIM21 as a novel host factor required by RABV for replication. Thus, TRIM21 is a potential target for rabies treatment or management.

Application of a novel multicomponent nanoemulsion to tumor therapy Based on the theory of "unification of drugs and excipients".

Toad skin has many pharmacological activities and bufadienolides are regarded as its main anti-tumor components. The poor water solubility, high toxicity, rapid elimination and less selectivity in vivo of bufadienolides limit the application of toad skin. Based on the "unification of drugs and excipients" theory, the toad skin extracts (TSE) and Brucea javanica oil (BJO) nanoemulsions (NEs) were designed to solve the aforementioned problems. BJO as the main oil phase was not only used to prepare the NEs, but played a synergistic therapeutic role combined with TSE. TSE-BJO NEs showed 155 nm particle size, entrapment efficiency of >95% and good stability. TSE-BJO NEs demonstrated superior anti-tumor activity compared with the TSE or BJO NEs alone. The mechanism of TSE-BJO NEs to enhance the antineoplastic efficacy involved several pathways, such as inhibiting cell proliferation, inducing tumor cell apoptosis >40% and arresting cell cycle at G2/M. TSE-BJO NEs could co-deliver drugs into the target cells efficiently and exhibit satisfying synergism. Besides, TSE-BJO NEs facilitated the long circulation of bufadienolides contributing to the high accumulation of drugs at tumor sites and the improvement of anti-tumor efficacy. The study achieves the combinative administration of the toxic TSE and BJO with high efficacy and safety.

[Analysis of clinical phenotype and variant of RAG1 gene in a child with B-cell-negative Severe Combined Immunodeficiency].

OBJECTIVE: To report on a child with B-cell-negative severe combined immunodeficiency (B-SCID) manifesting as fulminant myocarditis and carry out genetic testing for her. METHODS: A child with B-SCID who presented at Fujian Maternity and Child Health Care Hospital on January 31, 2021 was selected as the subject. Whole exome sequencing was carried out for her. Candidate variant was verified by Sanger sequencing. RESULTS: The female infant had developed recurrent skin and lung infections soon after birth, and was admitted due to fulminant myocarditis. Serological examination has disclosed a remarkable reduction in immunoglobulins. Flow cytometric analysis revealed that her peripheral blood T and B lymphocytes and NK cells were significantly reduced. Whole exome sequencing revealed that she has harbored a homozygous c.C3007T (p.Q1003X) nonsense variant of the RAG1 gene, for which both of her parents were heterozygous carriers. The variant has not been recorded in normal population databases. Based on the guidelines from the American College of Medical Genetics and Genomics, the variant was predicted to be pathogenic. CONCLUSION: A case of RAG1 gene associated B-SCID has been diagnosed. Above finding has enriched the spectrum of RAG1 gene variants and enabled early diagnosis and intervention of the disease.

[Analysis of PKP2 gene variants in a child with Arrhythmogenic right ventricular cardiomyopathy].

OBJECTIVE: To explore the clinical and genetic characteristics of a child with Arrhythmogenic right ventricular cardiomyopathy (ARVC). METHODS: A 6-year-old boy with ARVC who had visited Fujian Provincial Children's Hospital on August 23, 2022 was selected as the study subject. Relevant clinical data were collected, and peripheral venous blood samples were collected from the child and his parents for genetic testing through whole exome sequencing (WES). Sanger sequencing was carried out for family verification, and pathogenicity analysis was conducted for the candidate variants. RESULTS: The child had exhibited clinical symptoms including systemic edema, generalized heart enlargement, universal reduction of interventricular septum and ventricular wall movement, reduced left ventricular diastolic and systolic function, and reduced right ventricular systolic function. WES revealed that the child has harbored compound heterozygous variants of the PKP2 gene, namely c.119_122del (p.Leu40ArgfsTer71) and c.1978G>A (p.Gly660Arg), which were verified by Sanger sequencing to be respectively inherited from his father and mother. The c.119_122del variant has not been recorded in the 1000 Genomes, gnomAD and ExAC databases, and was predicted to lead to truncation of the PKP2 protein by SWISS-MODEL and PyMOL online software and classified as likely pathogenic based on the guidelines jointly developed by the American College of Medical Genetics and Genomics (ACMG) and ClinGen. The c.1978G>A variant has also not been recorded in the 1000 Genomes, gnomAD and ExAC databases, and was predicted to be deleterious by online software including REVEL, SIFT, CADD, Mutation Taster, and PolyPhen-2. The amino acid encoded by the variant site was highly conserved among various species by analysis using T-coffee and ESPript v3.0 online servers. The variant may affect the protein function by SWISS-MODEL and PyMOL online server analysis, and was classified as likely pathogenic based on the guidelines jointly developed by the ACMG and ClinGen. CONCLUSION: The compound heterozygous variants of c.119_122del (p.Leu40ArgfsTer71) and c.1978G>A (p.Gly660Arg) of the PKP2 gene probably underlay the ARVC in this child. Above finding has broadened the spectrum of PKP2 gene variants and provided a reference for the diagnosis and genetic counseling.

Diagnosis and genetic testing analysis of limb-girdle muscular dystrophy type 2U caused by a compound heterozygous mutation in the ISPD gene.

Limb-girdle muscular dystrophy (LGMD), a rare group of non-congenital inherited muscle diseases, is characterized by a progressive reduction in muscle tone and force of the proximal limbs. The clinical manifestations and genetic patterns of LGMD are heterogeneous. This study reported on a 10-year-old male patient with LGMD type 2U who experienced muscle weakness in the lower limbs after exercise. Upon admission, the patient's creatine kinase levels were significantly elevated, and hydration and alkalinization therapy were ineffective. Using high-throughput sequencing, muscular dystrophy-related genes were tested in the patient, his parents, and his sister. The patient was found to have a heterozygous deletion of exon 9 of the ISPD gene and a heterozygous missense mutation c.1231C>T (p.Leu411Phe). The patient's father carried the heterozygous missense mutation c.1231C>T (p.Leu411Phe) of the ISPD gene, while his mother and sister carried a heterozygous deletion of exon 9 of the ISPD gene. These mutations have not been reported in existing databases or literature. Conservation and protein structure prediction analyses of the mutation sites indicated that they are highly conserved and located in the C-terminal domain of the ISPD protein, which may affect protein function. Based on the above results and relevant clinical data, the patient was definitively diagnosed with LGMD type 2U. This study enriched the spectrum of ISPD gene mutations by summarizing the patient's clinical characteristics and analyzing new ISPD gene variations. This can aid in the early diagnosis and genetic counseling of the disease.